//复杂密码生成
function passwords(pasLen) {
    var password = '';
    var pasArr = ['a','b','c','d','e','f','g','h','i','j','k','l','m','n','o','p','q','r','s','t','u','v','w','x','y','z','A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P','Q','R','S','T','U','V','W','X','Y','Z','0','1','2','3','4','5','6','7','8','9'];
    var pasArrLen = pasArr.length;
    for (var i=0; i<pasLen; i++){
        var x = Math.floor(Math.random()*pasArrLen);
        password += pasArr[x];
    }
    console.log(password);
    return password;
}
